12" & >=90° Horn : where to cross over?

Heres pic of SLS12 response from manufacturers spec sheet.
If I hammer the breakup with notch, could it work? (XO at 1200Khz)

(12PR320 may be a clear winner already at this point concerning midrange quality but I'm ready to make compromises due to use only with movies and SLS12 better low end extension in sealed enclosure which could be integrated better with subs)
 

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thanks to share oceanw,

What about keeping the 12pr320 and work with the SLS below as a bass driver ? The SLS has a better usefull Fs : lower, for the bass. Could permit a low electrical slope between the two units. But 3 ways and less efficienty due to the SLS. best efficienty with the 12pr320 in BR is around 91.5 dB around 200 hz.

I do not know if this same idea could work at the sacrifice of 12PR320 efficienty if used open, still with the SLS BR.

On my side I didn't like finally the idea, but without tried a proof of concept, to use the 12PR320 that high, I keep it it till around 300 hz and purchased two 5.1/4" per side for MTM and WG tweeter (or not). Mabat horn project in hiatus for the moment.
 
Thanks for your thoughts diyiggy.

Youre right about 3-way but I kinda hope that SLS12 would work adequately in 2-way so I could save 12PR320 for other project in living room. This project is for bedroom cinema.
Also, my measurement space wont allow to rise speaker high enough to get accurate measurements under 650Hz, which I think would be important to get midwoofer and woofer XO´d at range of 250-400Hz.
When thinking about movie speaker I believe that larger cone (12-15") would produce more violent midbass and explosions if it can handle all bandwith of approx 80-700Hz by itself.
 
Heres updated data for 12PR320 and DFM2535 in 82L sealed test box (impedance and phase added, couldnt update earlier post anymore)
 

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  • 12PR320 and DFM-2535R00_ST260B phase.png
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  • 12PR320 and DFM-2535R00_ST260B resp.png
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  • 12PR320 and DFM-2535R00_ST260B.png
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My sim for 12PR320 in sealed (net 82L/2.9cu ft)

f3 89,8 Hz
f6 61,7 Hz
f10 43 Hz

In this sealed enclosure with DFM2535 and ST260B waveguide sound was clean, powerful and dynamic but without lowest bass. I had just one test speaker which was played middle of room at measurement point. Amp was Crown XLS1002 and I cranked volume quite hard, no problems. Especially electrical music sounded good, bass was snappy. Would have benefited from placement closer to the wall. Overall very promising, even with this bad placement and lack of lowest bass.
 
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Measured 12PR320 and Peerless DFM-2535R00-8 in ST260B horn.
Heres for start 12PR320 horizontal measurements from 1000mm distance. Any tips what scaling/limits in REW should be used?


View attachment 1117579
What a great response for a "pa" 12 inch, can be easily crossed at 1.2 khz and even higher, looks perfect for a 2 way, don't really see a reason to use a smaller mid in between for 3 way at home spl levels? Thanks for sharing your data, how do you like it now?
 
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... 2004 SP2 with same 15" woofer was rated 500 w AES with 2000 hz crossover. They abandoned the 3 db specification for 2004 but managed a -6 db width of 90 degrees by making the case narrower at the back..

...I measured my SP2(2004) on axis at 6' only 10 db down at 25 hz backed into a 1' thick plaster wall. So this explains why I have felt no need of a subwoofer. My house eliminates the BSC problem.
The 2004 spec sheet I found says 3db down at 54 and ~17k tuned to 55hz.
10 db down at 44 hz but we have our room gain.
Time delay 0,48ms
Minimum impedance 5,4 ohm
Max spl: Beyond Thunderous
If -20db below fundamental equals 2 % harmonic distortion it will have mostly below 1% and always below 2%.
When will you dissect yours and engineer a superior version for us to build?😉
Cheers!
 
What a great response for a "pa" 12 inch, can be easily crossed at 1.2 khz and even higher, looks perfect for a 2 way, don't really see a reason to use a smaller mid in between for 3 way at home spl levels? Thanks for sharing your data, how do you like it now?
It's indeed a great driver. Actually one of the best for 2-way duties. BUT, it's also specifically designed for bass reflex cabs.
However, the 16 Ohm version fares better in (rather large) sealed cabs.

In 200L:
1709891162237.png
 
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What if we tried the 8 ohm version in, for example, a 55L sealed enclosure and forced the response lower using moderately a Linkwitz Transform? Attached are the simulations with F3 of 51Hz. Or is the LT more suitable for subwoofers, and if used with a midbass, would it result in the loss of midrange reproduction quality because the cone moves with a larger excursion?
 

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  • FaitalPRO 12PR320 Excursion.png
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  • FaitalPRO 12PR320 SPL.png
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Personally I wouldn't use a LT for mid woofers such as the 12PR320 > I prefer to let drivers 'breath' as freely as possible.
A LT is a is a kind of band-aid that puts additional strain on the driver. The best excursion 'profile' is hardly any excursion at all 😉
 
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One may use this for bass:
1709960645470.png


and this for mids:
1709960689243.png

with respectively 11 and 6.5mm Xmax.

Or one could use several of these, or something similar:
1709961769326.jpeg


Lately I've been selecting woofers mostly based on cone material + low Xmax in order to approach that glorious, rich vintage sound signature.
Of course taking into account the application.
 
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Hi Zvu,

I took just horizontal measurements according Kimmostos Vcad instructions with 10° increments. Nowadays I have better measuring space with thick absorption panels in floor and ceiling & left to right. Used Steinberg UR22 mkII and EMX-7150. I can send files if someone needs them. Does my measurement deviate from your Hor set? Im finishing some waveguides soon and start measuring different woofer modules in new measuring space/room.
 
My sim for 12PR320 in sealed (net 82L/2.9cu ft)

f3 89,8 Hz
f6 61,7 Hz
f10 43 Hz

In this sealed enclosure with DFM2535 and ST260B waveguide sound was clean, powerful and dynamic but without lowest bass. I had just one test speaker which was played middle of room at measurement point. Amp was Crown XLS1002 and I cranked volume quite hard, no problems. Especially electrical music sounded good, bass was snappy. Would have benefited from placement closer to the wall. Overall very promising, even with this bad placement and lack of lowest bass.

Unless you must have (~are married to) sealed, a 55l box tuned @ 45 Hz looks like this:

1710140151776.png

However, you could experiment with 'lossy/aperiodic' vents > oversized ports stuffed with open cell foam or something similar.

Example:
1710143236585.png


Since your cabs are 82l, some additional low-end extension is at hand. 82l @ 46Hz:

1710141012522.png

It's a matter of preference/taste of course, but especially with electronic music I find many sealed systems often sound too dry, depending on placement/space.
 
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